Glass articles, such as bottles and jars but herein exemplified by bottles, are typically mass produced in a glassware forming machine. A glassware forming machine is formed by combining or integrating a plurality of individual sections. Each individual section (IS or Section) is capable of producing one to four bottles simultaneously from a similar number of gobs of molten glass. By combining a relatively large number of Sections in a single glassware forming machine, a relatively high capacity for bottle production capacity is achieved. Furthermore, the operation of each Section is coordinated with all of the Sections so that the glassware forming machine achieves an unrestricted production output equal to the cumulative total of the individual capacities of all of the Sections.
One approach to increasing efficiency and profitability in the glass forming industry is to increase bottle production rates. Increasing the manufacturing capacity may be achieved by increasing the number of Sections of a single glassware forming machine. However, substantially increasing the number of Sections may result in a practical problem of difficulty in removing or transporting the bottles away from the glassware forming machine at the same high rate that all of the Sections are capable of producing bottles. If the bottles cannot be removed as fast as the Sections make them, the overall capacity of the glassware forming machine will be diminished and the desired increase in production from combining a larger number of Sections will be lost.
In a conventional IS, a take-out mechanism removes the bottles from a blow mold after they have been formed into the final desired shape and deposits the bottles on a dead plate. A pusher mechanism then moves the bottles from the dead plate onto an adjacent, fast-moving transfer conveyor which removes the still-hot, but fully-formed, bottles to an annealing Lehr, for further treatment to complete the bottle-making procedure. The transfer conveyor typically removes the bottles from the glassware forming machine in a single line in single file so that a transfer wheel can align the bottles and the bottles can be pushed in single bottle rows into the annealing furnace.
The transfer conveyor moves at essentially a right angle to the direction in which the take-out mechanism removes the bottles from the blow molds. The pusher mechanism must therefore alter the orientation of the aligned bottles by ninety degrees while transferring the bottles to empty spaces or "windows" unoccupied by other bottles on the transfer conveyor. The pusher mechanism should also accelerate the bottles to approximately the linear speed of the transfer conveyor so the bottles will remain upright on the conveyor without tipping when they are deposited on the transfer conveyor.
A conventional pusher mechanism typically accomplishes these functions with a rotary motion. The bottles are moved along an arcuate path to change their orientation by the ninety degrees and align their orientation parallel to the transfer conveyor while simultaneously accelerating the bottles along the arcuate path so they achieve a linear speed approximately equal to the speed of the conveyor at the end of the arcuate movement. With this acceleration, the linear velocity of the bottles in the direction of the conveyor approximately matches the speed of the conveyor. By matching the linear velocity of the transferred bottles to the speed of the conveyor, there is little or no relative motion between the bottles and the conveyor when they are delivered to the conveyor. Consequently no significant instabilities are introduced. Instabilities could cause tipping and subsequent destruction of the bottles or misalignment of bottles on the conveyor, or could cause the bottles to contact one another (which would likely create defects within the bottles due to their high temperature).
Although prior art rotary pusher mechanisms are adequate for use with many conventional glassware forming machines, they have proved problematic in glassware forming machines having a relatively large number of Sections operating at full capacity. The problems arise because a higher speed transfer conveyor is needed to remove the increased number of bottles formed by the higher capacity glassware forming machine. The greater speed of the conveyor requires the pusher mechanism to rotate with a greater angular velocity to accelerate the bottles to a speed which will match the speed of the conveyor at the end of the arcuate movement. At the higher angular velocity, the centrifugal force acting on the bottles, which increases by the square of the increase in angular velocity, creates unacceptable instabilities which tend to throw the bottles out of contact with the pusher mechanism, throw the bottles off of the conveyor, tip the bottles, position the bottles out of alignment on the conveyor, or the like. Reducing the angular velocity of the prior art rotary pusher to limit the amount of centrifugal force causes an unacceptable mismatch in the linear speed the bottles and the speed of the conveyor, and this mismatch in speed could be sufficiently destabilizing to cause the bottles to tip, to contact other bottles to be out of alignment on the conveyor, or the like. Of course, reducing the angular velocity of the prior art rotary pusher mechanism may also have the undesirable effect of slowing the operating speed of the IS, thus reducing the output capacity of the glassware forming machine.
Consequently, the limitations of prior art rotary pusher mechanisms have practically limited the output capacity of glassware forming machines to approximately their current levels. It is with respect to the prior art rotary pusher mechanisms' practical restrictions on the further increase in capacity of glassware forming machines, as well as other considerations not specifically discussed in this abbreviated background, that the present invention has evolved.